Re: [sqlite] GUID/UUID in sqlite.

[Scott Hess]

In either case, if you use the UUID as a primary key in more than one
table, you should consider having one table to convert the UUID to a
64-bit id, and use that as the primary keys on the other tables.  If
you have UUID as a primary key, your table will have 2 b-trees, one
for the index of UUID to rowid, the other to map the rowid to row
data.  Once you have 2 such tables, it can be more efficient to break
out the mapping of the UUID to an internal id you use elsewhere.

Example, instead of:

CREATE TABLE t (
  uuid TEXT PRIMARY KEY,
  ...
);
INSERT INTO t (uuid, ...) VALUES (?, ...);

Do:

CREATE TABLE u (
  uuid TEXT UNIQUE,
  internalid INTEGER PRIMARY KEY
);
CREATE TABLE t (
  fk_internalid INTEGER PRIMARY KEY,
  ...
);
BEGIN;
INSERT INTO u (uuid, internalid) VALUES (?, NULL);
INSERT INTO t (fk_internalid, ...) VALUES (LAST_INSERT_ROWID(), ...);
COMMIT;

-scott


On 8/29/07, John Stanton <[EMAIL PROTECTED]> wrote:
> You could experiment with making your 128 bit entity a BLOB.  The
> alternative would be to represent it it in ASCII.  Changing its radix
> would probably be the significant overhead, not the Sqlite storage.
>
> Prakash Reddy Bande wrote:
> > Hi,
> >
> > I am designing a database where-in my column data is UUID.
> > I am trying to figure out which is the best way to handle UUID since if
> > stored as text the length would be 32 characters (though UUIDs are 128
> > bit size) and select query based on UUIDs might not be really fast (I
> > might be wrong here.)
> >
> > Regards,
> >
> > Prakash Reddy Bande
> > Altair Engg. Inc,
> > Troy, MI
> >
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